SQL Server中的输入参数和数据类型问题

Question

I have a table called report with 3 columns:

reportdate date, name varchar(10), location varchar(10) 

Sample data:

reportdate  name  location  
-------------------------------
2014-01-01  sachin  vizag  
2014-02-02  tendulkar   vizag  
2014-03-03  ram vizag  
2014-04-04  robert  vizag  
2014-05-05  rahim   vizag  
2014-06-06  king    vizag  
2013-01-01  sachin  vizag  
2013-02-02  tendulkar   vizag  
2013-03-03  ram vizag  
2013-04-04  robert  vizag  
2013-05-05  rahim   vizag  
2013-06-06  king    vizag    

Sample SQL Fiddle

My actual requirement was to create a date parameter for SSRS reports. So I have taken reportdate column for that purpose.

I need to create 3 parameters from single reportdate column

Parameter 1 :

I need to select only year value from reportdate column, for which I used this query

select distinct YEAR(ReportDate) as ReportYear 
from report  

and the result of it was

ReportYear
----------
2013
2014

Parameter 2:

I need to create a parameter for months column and this is the stored procedure which I have created

create procedure months 
    @years date
as begin
   select distinct  
      Case
         When CONVERT(varchar(2), ReportDate, 101) = 01 Then 'JAN'
         When CONVERT(varchar(2), ReportDate, 101) = 02 Then 'FEB'
         When CONVERT(varchar(2), ReportDate, 101) = 03 Then 'MAR'
         When CONVERT(varchar(2), ReportDate, 101) = 04 Then 'APR'
         When CONVERT(varchar(2), ReportDate, 101) = 05 Then 'MAY'
         When CONVERT(varchar(2), ReportDate, 101) = 06 Then 'JUN'
         When CONVERT(varchar(2), ReportDate, 101) = 07 Then 'JUL'
         When CONVERT(varchar(2), ReportDate, 101) = 08 Then 'AUG'
         When CONVERT(varchar(2), ReportDate, 101) = 09 Then 'SEP'
         When CONVERT(varchar(2), ReportDate, 101) = 10 Then 'OCT'
         When CONVERT(varchar(2), ReportDate, 101) = 11 Then 'NOV'
         When CONVERT(varchar(2), ReportDate, 101) = 12 Then 'DEC'
      end ReportMonth
       --,year(reportdate) As ReportYear 
   from 
      report
   where 
      reportdate in (select CAST(cast(@years as datetime)as date))
      --order by DATEPART(m,ReportMonth)

end   

I am passing years as parameter in the above procedure, if I pass value 2013/2014 as parameter then my output has to be as below

ReportMonth ReportYear
-----------------------
JAN 2014
FEB 2014
MAR 2014
APR 2014
MAY 2014
JUN 2014
JAN 2013
FEB 2013
MAR 2013
APR 2013
MAY 2013
JUN 2013  

instead of the above output I am getting below output if I run the above stored procedure for year 2013.

ReportMonth ReportYear
------------------------
JAN 2013  

I don't understand why only one month is being populated instead of all the available months in the table.

Answer 1

I would say your where clause doesn't look correct. You should be checking the DATEPART (YEAR,reportdate) to equal the year you passed as a parameter to your stored procedure.

Your WHERE clause checks if reportdate is IN a set with only one date, which equals the 1 january of that year. This is obviously not what you want.

Answer 2

If you want to pass parameters as for example 2013/2014 you probably need to use a function to split the parameters (there are plenty of examples of split functions around the net), but if you don't want to handle splitting parameters one way to accomplish this is to use dynamic sql in the procedure:

CREATE PROC Months @YEARS VARCHAR(50)
AS
BEGIN
DECLARE @SQL VARCHAR(500) = 
'SELECT DISTINCT 
    MONTH(ReportDate) AS [Month], 
    UPPER(LEFT(DATENAME(MONTH,ReportDate),3)) AS ReportMonth, 
    YEAR(ReportDate) AS ReportYear 
FROM Report 
WHERE YEAR(ReportDate) IN (' + @YEARS + ')
ORDER BY ReportYear DESC, [Month]'
EXEC (@SQL)
END;

I included the month number for sorting (and it might be good to have too).

When called as EXEC Months '2013, 2014' this would output:

Month       ReportMonth ReportYear
----------- ----------- -----------
1           JAN         2014
2           FEB         2014
3           MAR         2014
4           APR         2014
5           MAY         2014
6           JUN         2014
1           JAN         2013
2           FEB         2013
3           MAR         2013
4           APR         2013
5           MAY         2013
6           JUN         2013

Another option would be to create a table valued type, declare a variable based on that type, insert the years you want to filter by and have the procedure accept a table valued type as parameter:

CREATE TYPE YearsType AS TABLE (Y INT)
GO 
CREATE PROC M @YEARS YearsType READONLY
AS
SELECT DISTINCT 
    MONTH(ReportDate) AS [Month], 
    UPPER(LEFT(DATENAME(MONTH,ReportDate),3)) AS ReportMonth, 
    YEAR(ReportDate) AS ReportYear 
FROM Report 
WHERE YEAR(ReportDate) IN (SELECT Y FROM @YEARS)
ORDER BY ReportYear DESC, [Month]
GO

DECLARE @Years YearsType
--INSERT @Years VALUES (2013)
INSERT @Years VALUES (2013),(2014)
EXECUTE M @YEARS 

This obviously has some drawbacks in that you need to declare a local table variable and populate it before calling the procedure.

Sample SQL Fiddle for both versions above.